Hub

ABSTRACT

A hub including a first connection interface, a second connection interface, and a signal bypass circuit is provided. The first connection interface has a first pin to receive a first connection message. The second connection interface has a second pin to transmit the first connection message. The signal bypass circuit is coupled to the first pin and the second pin to decide whether to bypass the first pin and the second pin based on the first connection message.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 106108869, filed on Mar. 17, 2017. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a hub, particularly a hub having a signalbypass function.

Description of Related Art

The external interfaces of electronic devices reduce in size as theelectronic devices are manufactured thinner and lighter, leading to acontinual decrease in the number of external devices that can bedirectly coupled to the electronic devices. When coupling too manyexternal devices, users would apply a hub to connect the externaldevices to an electronic device. Additionally, as communicationtechnology progresses, external devices are able to perform simplecommunication with the electronic devices to enable the synchronizedoperation between the external devices and the electronic devices. As aresult, a circuit of the hub must be designed in consideration of theinteraction between the external devices and the electronic devices toensure their smooth connection and avoid interfering with theirsynchronized operation.

SUMMARY OF THE INVENTION

The invention provides a hub capable of bypassing a first pin and asecond pin, so as to avoid interfering with a synchronized operationbetween an external device and an electronic device.

A hub of the invention includes a first connection interface, a secondconnection interface, and a signal bypass circuit. The first connectioninterface has a first pin to receive a first connection message. Thesecond connection interface has a second pin configured to transmit thefirst connection message. The signal bypass circuit is coupled to thefirst pin and the second pin, so as to decide whether to bypass thefirst pin and the second pin based on the first connection message.

A hub of the invention includes a first universal serial bus (USB)c-type interface, a second USB c-type interface, a firsttransmission/receipt circuit, a second transmission/receipt circuit, acontrolling circuit, and a signal bypass circuit. The first USB c-typeinterface has a first channel configuration pin to receive a firstconnection message. The first transmission/receipt circuit is coupled tothe first USB c-type interface and receives the first connection messageto provide a connection configuration signal. The second USB c-typeinterface has a second channel configuration pin configured to transmitthe first connection message. The second transmission/receipt circuit iscoupled to the second channel configuration pin and is configured torestore the connection configuration signal to the first connectionsignal. The controlling circuit is coupled to the firsttransmission/receipt circuit and the second transmission/receiptcircuit, so as to receive the connection configuration signal andprovide a transmission switch signal based on the connectionconfiguration signal. The signal bypass circuit is coupled to the firsttransmission/receipt circuit, the second transmission/receipt circuit,and the controlling circuit, so as to decide whether to bypass the firsttransmission/receipt circuit and the second transmission/receipt circuitbased on the connection configuration signal and the transmission switchsignal.

A hub of the invention includes a first pin, a second pin, and a signalbypass circuit. The first pin is coupled to a first universal serial bus(USB) c-type device to receive a first connection message. The secondpin is coupled to a second USB c-type device to transmit the firstconnection message to the second USB c-type device. The signal bypasscircuit is coupled to the first pin and the second pin to decide whetherto bypass the first pin and the second pin based on the first connectionmessage.

Based on the above, the signal bypass circuit of the hub in theembodiment of the invention is coupled to the first pin of the firstconnection interface and the second pin of the second connectioninterface, so as to decide whether to bypass the first pins and thesecond pins based on the first connection message received by the firstpin. In this way, the hub is able to bypass the first pin and the secondpin when the hub cannot intermediate a host and the external device, soas to avoid interfering with the synchronized operation between theexternal device and the electronic device.

To make the aforementioned and other features and advantages of theinvention more comprehensible, several embodiments accompanied withdrawings are described in detail as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate exemplaryembodiments of the invention and, together with the description, serveto explain the principles of the invention.

FIG. 1 is a systematic diagram of a hub according to the firstembodiment of the invention.

FIG. 2 is a systematic diagram of a hub according to the secondembodiment of the invention.

FIG. 3 is a systematic diagram of a hub according to the thirdembodiment of the invention.

FIG. 4 is a systematic diagram of a hub according to the fourthembodiment of the invention.

FIG. 5 is a flow chart of an operating method of a receiving end of ahub according to an embodiment of the invention.

FIG. 6 is a flow chart of an operating method of a transmitting end of ahub according to an embodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a systematic diagram of a hub according to the firstembodiment of the invention. Please refer to FIG. 1. In this embodimentof the invention, a hub 100 includes a first connection interface IF11,a second connection interface IF12, and a signal bypass circuit 110. Thefirst connection interface IF11 is adapted to be coupled to a host 10and the second connection interface IF12 is adapted to be coupled to anexternal device 20. The external device 20 may be an adapter, a securitykey, or a device similar thereto.

In this embodiment of the invention, the first connection interface IF11and the second connection interface IF12 may be a universal serial bus(USB) c-type interface. In other words, the first connection interfaceIF11 (i.e. a first USB c-type interface) at least has first pins, whichare first channel configuration pins CC1 a and CC2 a. The secondconnection interface IF12 (i.e. a second USB c-type interface) at leasthas second pins, which are second channel configuration pins CC1 b andCC2 b. Accordingly, the host 10 and the external device 20 arerespectively a USB c-type device having the USB c-type interface.

The first pin (such as the first channel configuration pin CC1 a or CC2a) is configured to receive a first connection message MC1 x provided bythe host 10. The second pin (such as the second channel configurationpin CC1 b or CC2 b) is configured to transmit a first connection messageMC1 r passing through the signal bypass circuit 110 to the externaldevice 20. Meanwhile, the signal bypass circuit 110 decides whether tobypass the first pin (such as the first channel configuration pin CC1 aor CC2 a) and the second pin (such as the second channel configurationpin CC1 b or CC2 b) based on the first connection message MC1 x.

On the contrary, the second pin (such as the second channelconfiguration pin CC1 b or CC2 b) is configured to receive a secondconnection message MC2 x provided by the external device 20. The firstpin (such as the first channel configuration pin CC1 a or CC2 a) isconfigured to transmit a second connection message MC2 r passing throughthe signal bypass circuit 110 to the host 10. Meanwhile, the signalbypass circuit 110 decides whether to bypass the first pin (such as thefirst channel configuration pins CC1 a or CC2 a) and the second pin(such as the second channel configuration pin CC1 b or CC2 b) based onthe second connection message MC2 x.

In this embodiment of the invention, the signal bypass circuit 110 mayalternately bypass and disconnect. Alternatively, the signal bypasscircuit 110 may only bypass the first pin (such as the first channelconfiguration pins CC1 a or CC2 a) and the second pin (such as thesecond channel configuration pin CC or CC2 b) once when the hub 100 issimultaneously coupled to the host 10 and the external device 20. And,the signal bypass circuit 110 may disconnect from the first pin (such asthe first channel configuration pin CC1 a or CC2 a) and the second pin(such as the second channel configuration pins CC1 b or CC2 b) when thehub 100 disconnects from either of the host 10 and the external device20. Whether bypassing of the signal bypass circuit 110 may be decidedaccording to information sensed by a signal, a content of a register, oran operation of firmware.

In this embodiment of the invention, the first pin (such as the firstchannel configuration pin CC1 a or CC2 a) and the second pin (such asthe second channel configuration pin CC1 b or CC2 b) may be pre-set tobe bypassed.

Additionally, assuming the signal bypass circuit 110 is disconnectedfrom the first pin (such as the first channel configuration pin CC1 a orCC2 a) and the second pin (such as the second channel configuration pinCC or CC2 b) before the host 10 transmits the first connection messageMC1 x, then the signal bypass circuit 110 continues to disconnect fromthe first pin (such as the first channel configuration pin CC1 a or CC2a) and the second pin (such as the second channel configuration pin CC1b or CC2 b) when the first pin (such as the first channel configurationpin CC1 a or CC2 a) does not receive the first connection message MC1 x;and the signal bypass circuit 110 bypasses the first pin (such as thefirst channel configuration pin CC1 a or CC2 a) and the second pin (suchas the second channel configuration pin CC or CC2 b) when the first pin(such as the first channel configuration pin CC1 a or CC2 a) receivesthe first connection message MC1 x.

Alternatively, the signal bypass circuit 110 disconnects from the firstpin (such as the first channel configuration pin CC1 a or CC2 a) and thesecond pin (such as the second channel configuration pin CC1 b or CC2 b)and is replying the message in advance when the signal bypass circuit110 determines that the first connection message MC1 x can be repliedbased on head data of the first connection message MC1 x. The signalbypass circuit 110 bypasses the first pin (such as the first channelconfiguration pin CC1 a or CC2 a) and the second pin (such as the secondchannel configuration pin CC1 b or CC2 b) but does not react to thefirst connection message MC1 x when the signal bypass circuit 110determines that the first connection message MC1 x cannot be repliedbased on the head data of the first connection message MC1 x.

Further in the alternative, the signal bypass circuit 110 disconnectsfrom the first pin (such as the first channel configuration pin CC1 a orCC2 a) and the second pin (such as the second channel configuration pinCC1 b or CC2 b) when the first connection message MC1 x is nottransmitting a command. The signal bypass circuit 110 bypasses the firstpin (such as the first channel configuration pin CC1 a or CC2 a) and thesecond pin (such as the second channel configuration pin CC1 b or CC2 b)when the first connection message MC1 x is transmitting a command.

FIG. 2 is a systematic diagram of a hub according to the secondembodiment of the invention. Please refer to FIG. 1 and FIG. 2, whereinidentical or similar reference numerals are used on identical or similarelements. In this embodiment of the invention, a hub 200 includes afirst connection interface IF21, a second connection interface IF22, asignal bypass circuit 210, a controlling circuit 220, a first logiccircuit 230, a second logic circuit 240, a first transmission/receiptcircuit 250, a second transmission/receipt circuit 260, a first powerswitch PS1, and a second power switch PS2.

In this embodiment of the invention, the first connection interface IF21depicts not only first channel configuration pins CC1 a and CC2 a, but afirst power pin VBUSa. Furthermore, the second connection interface IF22depicts not only second channel configuration pins CC1 b and CC2 b, buta second power pin VBUSb.

A first end of the first power switch PS1 is coupled to the first powerpin VBUSa. A controlling end of the first power switch PS1 is coupled tothe controlling circuit 220, so as to receive a first power switchsignal SPS1 of a power switch signal SPS provided by the controllingcircuit 220. A first end of the second power switch PS2 is coupled tothe second power pin VBUSb. A controlling end of the second power switchPS2 is coupled to the controlling circuit 220, so as to receive a secondpower switch signal SPS2 of the power switch signal SPS provided by thecontrolling circuit 220. A second end of the second power switch PS2 iscoupled to a second end of the first power switch PS1.

The first logic circuit 230 is coupled to the first channelconfiguration pins CC1 a and CC2 a, the controlling circuit 220, and thefirst transmission/receipt circuit 250, so as to set a voltage level ofthe first channel configuration pins CC1 a and CC2 a based on a firstlevel setting signal SLC1 of a level setting signal SLC provided by thecontrolling circuit 220. The second logic circuit 240 is coupled to thesecond channel configuration pins CC and CC2 b, controlling circuit 220,and the second transmission/receipt circuit 260, so as to set a voltagelevel of the second channel configuration pins CC1 b and CC2 b based ona second level setting signal SLC2 of the level setting signal SLCprovided by the controlling circuit 220.

The first transmission/receipt circuit 250 is coupled between the signalbypass circuit 210, the controlling circuit 220, and the first logiccircuit 230. In other words, the first transmission/receipt circuit 250is coupled between the first channel configuration pins CC1 a and CC2 a,the signal bypass circuit 210, and the controlling circuit 220. Thesecond transmission/receipt circuit 260 is coupled between the signalbypass circuit 210, the controlling circuit 220, and the second logiccircuit 240. In other words, the second transmission/receipt circuit 260is coupled between the second channel configuration pins CC1 b and CC2b, the signal bypass circuit 210, and the controlling circuit 220.

In this embodiment of the invention, the controlling circuit 220 setsthe voltage level of the first channel configuration pins CC1 a and CC2a through the first level setting signal SLC1, so as to perform amatching operation between the hub 200 and a host 10 when either of thefirst channel configuration pins CC1 a and CC2 a is coupled to the host10. Moreover, the host 10 is pre-set to provide a power voltage VH1 tothe first power pin VBUSa. The first power switch PS1, however, issubjected to the first power switch signal SPS1 and remains cutoff.

The controlling circuit 220 also sets the voltage level of the secondchannel configuration pins CC1 b and CC2 b through the second levelsetting signal SLC2, so as to perform a matching operation between thehub 200 and an external device 20 when either of the second channelconfiguration pins CC1 b and CC2 b is coupled to the external device 20.When the external device 20 is a security key or a similar devicewithout power-supply ability, the first power switch PS1 is subjected tothe first power switch signal SPS1 and is conducted, and the secondpower switch PS2 is subjected to the second power switch signal SPS2 andis conducted after the hub 200 and the external device 20 finishmatching, so as to provide the power voltage VH1 to the external device20 through the second power pin VBUSb.

When the external device 20 is an adapter or a similar device, theexternal device 20 is pre-set to provide a power voltage VH2 to thesecond power pin VBUSb. Meanwhile, the controlling circuit 220 againsets the voltage level of the first channel configuration pins CC1 a andCC2 a through the first level setting signal SLC1, so as to perform are-matching operation between the hub 200 and the host 10 and to furthermake the host 10 stop providing the power voltage VH1. The first powerswitch PS1 is subjected to the first power switch signal SPS1 and isconducted, and the second power switch PS2 is subjected to the secondpower switch signal SPS2 and is conducted after the host 10 stopsproviding the power voltage VH1, so as to provide the power voltage VH1to the host 10 through the first power pin VBUSa.

On the other hand, the first channel configuration pin CC1 a or CC2 amay receive a first connection message MC1 x provided by the host 10,and the second channel configuration pin CC1 b or CC2 b may receive asecond connection message MC2 x provided by the external device 20 whenthe hub 200, the host 10, and the external device 20 finish matching (orre-matching).

The first connection message MC1 x is transmitted to the firsttransmission/receipt circuit 250 through the first logic circuit 230when either of the first channel configuration pins CC1 a and CC2 areceives the first connection message MC1 x provided by the host 10. Thefirst transmission/receipt circuit 250 provides a connectionconfiguration signal SCC to the signal bypass circuit 210 and thecontrolling circuit 220 after receiving the first connection message MC1x. In other words, the first connection message MC1 x and the connectionconfiguration signal SCC have the same meaning but are of differentsignal types.

When receiving the connection configuration signal SCC, the controllingcircuit 220 provides a transmission switch signal STS to the signalbypass circuit 210 based on the connection configuration signal SCC anddetermines whether the connection configuration signal SCC needs toreply. The controlling circuit 220 transmits a connected signal GCr tothe first channel configuration pin CC1 a or CC2 a through the firsttransmission/receipt circuit 250 when the connection configurationsignal SCC (i.e. the first connection message MC1 x) needs to reply theconnected signal GCr. The controlling circuit 220 does not transmit theconnected signal GCr when the connection configuration signal SCC doesnot need to reply the connected signal GCr.

Following the above, the signal bypass circuit 210 decides whether totransmit the connection configuration signal SCC to the secondtransmission/receipt circuit 260 based on the connection configurationsignal SCC and the transmission switch signal STS. In other words, thesignal bypass circuit 210 decides whether to bypass the firsttransmission/receipt circuit 250 and the second transmission/receiptcircuit 260. The second transmission/receipt circuit 260 restores theconnection configuration signal SCC to the first connection message MC1r and transmits the first connection message MC1 r to the externaldevice 20 through the second logic circuit 240 and the second channelconfiguration pin CC1 b or CC2 b when receiving the connectionconfiguration signal SCC. In a similar manner, the second channelconfiguration pin CC1 b or CC2 b performs a signal transmissionoperation similar to the above when receiving the second connectionmessage MC2 x.

In this embodiment of the invention, the signal bypass circuit 210 maydisconnect from the first transmission/receipt circuit 250 and thesecond transmission/receipt circuit 260 when the signal bypass circuit210 does not receive the connection configuration signal SCC. The signalbypass circuit 210 may bypass the first transmission/receipt circuit 250and the second transmission/receipt circuit 260 when the signal bypasscircuit 210 receives the connection configuration signal SCC.

Alternatively, the signal bypass circuit 210 may disconnect from thefirst transmission/receipt circuit 250 and the secondtransmission/receipt circuit 260 when the signal bypass circuit 210determines that the connection configuration signal SCC can be repliedbased on head data of the connection configuration signal SCC. Thesignal bypass circuit 210 may bypass the first transmission/receiptcircuit 250 and the second transmission/receipt circuit 260 when thesignal bypass circuit 210 determines that the connection configurationsignal SCC cannot be replied based on the head data of the connectionconfiguration signal SCC.

Further in the alternative, the signal bypass circuit 210 disconnectsfrom the first transmission/receipt circuit 250 and the secondtransmission/receipt circuit 260 when the connection configurationsignal SCC is not transmitting a command. The signal bypass circuit 210bypasses the first transmission/receipt circuit 250 and the secondtransmission/receipt circuit 260 when the connection configurationsignal SCC is transmitting a command.

In this embodiment of the invention, the signal bypass circuit 210includes a first signal switch SSW1, a first bypass arbitration circuitBAR1, a second bypass arbitration circuit BAR2, and a second signalswitch SSW2. The first bypass arbitration circuit BAR1 includes a firstbypath switch BSW1 and a first determining circuit DTC1. The secondbypass arbitration circuit BAR2 includes a second bypath switch BSW2 anda second determining circuit DTC2. A first end of the first signalswitch SSW1 is coupled to the first transmission/receipt circuit 250 toreceive the connection configuration signal SCC. A controlling end ofthe first signal switch SSW1 receives a first transmission switch signalSTS1 of the transmission switch signal STS.

A first end of the first bypath switch BSW1 is coupled to a second endof the first signal switch SSW1. A controlling end of the first bypathswitch BSW1 is coupled to the first determining circuit DTC1 to receivea first bypath signal SB1. The first determining circuit DTC1 is coupledto the second end of the first signal switch SSW1, the controlling endof the first bypath switch BSW1, and the second end of the first bypathswitch BSW1, and receives the connection configuration signal SCC toprovide the first bypath signal SB1.

A first end of the second signal switch SSW2 is coupled to the secondtransmission/receipt circuit 260. A controlling end of the second signalswitch SSW2 receives a second transmission switch signal STS2 of thetransmission switch signal STS. A first end of the second bypath switchBSW2 is coupled to a second end of the second signal switch SSW2. Acontrolling end of the second bypath switch BSW2 is coupled to thesecond determining circuit DTC2 to receive a second bypath signal SB2.The second determining circuit DTC2 is coupled to the second end of thesecond signal switch SSW2, the controlling end of the second bypathswitch BSW2, and a second end of the second bypath switch BSW2, andreceives the connection configuration signal SCC to provide the secondbypath signal SB2.

In this embodiment of the invention, the controlling circuit 220 maycontinue to monitor the connection configuration signal SCC to determinewhether the connection configuration signal SCC is correct. Thecontrolling circuit 220 may disconnect from the signal bypass circuit210 through the transmission switch signal STS when the connectionconfiguration signal SCC is incorrect. The controlling circuit 220 maycontinue to conduct the signal bypass circuit 210 through thetransmission switch signal STS when the connection configuration signalSCC is correct.

In this embodiment of the invention, the hub 200 may be divided into twomain parts, i.e., a PA part and a PB part, according to a signalprocessing procedure. The PA part and the PB part may be respectivelytaken as a receiving end and a transmitting end. As shown in FIG. 2, thePA part includes the first connection interface IF21, the first logiccircuit 230, the first transmission/receipt circuit 250, a left half ofthe signal bypass circuit 210 that is coupled to the firsttransmission/receipt circuit 250, and a left half of the controllingcircuit 220 that is coupled to the first transmission/receipt circuit250. The PB part includes the second connection interface IF22, thesecond logic circuit 240, the second transmission/receipt circuit 260, aright half of the signal bypass circuit 210 that is coupled to thesecond transmission/receipt circuit 260, and a right half of thecontrolling circuit 220 that is coupled to the secondtransmission/receipt circuit 260. For instance, the PA part may be takenas the receiving end and the PB part may be taken as the transmittingend when either of the first channel configuration pins CC1 a and CC2 areceives the first connection message MC1 x provided by the host 10; thePB part may be taken as the receiving end and the PA part may be takenas the transmitting end when the second channel configuration pin CC1 bor C22 b receives the second connection message MC2 x.

In this embodiment of the invention, the controlling circuit 220 may beconstructed with a single integrated circuit (chip) to simultaneouslymanage the PA part and the PB part. The controlling circuit 220 may alsobe constructed with two chip to respectively manage the PA part and thePB part. Such construction may be decided by people with ordinary skillsin the art of the field and the embodiment of the invention is notlimited thereto.

FIG. 3 is a systematic diagram of a hub according to the thirdembodiment of the invention. Please refer to FIG. 1 to FIG. 3. A hub 300is generally identical to the hub 200 but is different in a controllingcircuit 320, wherein identical or similar reference numerals are used onidentical or similar elements. In this embodiment of the invention, thecontrolling circuit 320 is not coupled to the first transmission/receiptcircuit 250 and the second transmission/receipt circuit 260. In otherwords, a first signal switch SSW1 and a second signal switch SSW2 areconducted to reduce functions of the controlling circuit 320 anddecrease a circuit area of the controlling circuit 320 when either offirst channel configuration pins CC1 a and CC2 a is coupled to a host 10and/or either of second channel configuration pins CC2 a and CC2 b iscoupled to an external device 20.

FIG. 4 is a systematic diagram of a hub according to the fourthembodiment of the invention. Please refer to FIG. 2 and FIG. 4. A hub400 is generally identical to the hub 200 but is different in a signalbypass circuit 410, a controlling circuit 420, a first buffer BF1, and asecond buffer BF2, wherein identical or similar reference numerals areused on identical or similar elements.

In this embodiment of the invention, the first buffer BF1 is coupledbetween a first transmission/receipt circuit 250, the controllingcircuit 420, and the signal bypass circuit 410, so as to buffer aconnection configuration signal SCC. The second buffer BF2 is coupledbetween a second transmission/receipt circuit 260, the controllingcircuit 420, and the signal bypass circuit 410, so as to buffer theconnection configuration signal SCC.

The controlling circuit 420 reads the connection configuration signalSCC stored by the first buffer BF1 and decides whether to enable atransmission switch signal STSa based on the connection configurationsignal SCC when the first channel configuration pin CC1 a or CC2 areceives a first connection message MC1 x provided by the host 10. Thesignal bypass circuit 410 bypasses the first buffer BF1 and the secondbuffer BF2 to transmit the connection configuration signal SCC to thesecond buffer BF2 when the transmission switch signal STSa is enabled.

In this embodiment of the invention, the signal bypass circuit 410 maybe constructed with a switch or referred to a circuit design of thesignal bypass circuit 210. Nevertheless, here is determined based on acircuit design thereof, and the invention is not limited thereto.

FIG. 5 is a flow chart of an operating method of a receiving end of ahub according to an embodiment of the invention. Please refer to FIG. 5.In this embodiment of the invention, the operating method of thereceiving end of the hub includes the following steps. In step S510, itis determined whether the connection interface is coupled to the device.If the connection interface is not coupled to the device, which means adetermining result of the step S510 is “no”, then it restarts from thestep S510. If the connection interface is coupled to the device, whichmeans the determining result of the step S510 is “yes”, then it proceedsto execute step S520.

In the step S520, it is determined whether the connection interfacereceives the connection message and whether the connection message meetsoutput criteria. If the connection message does not meet the outputcriteria, which means a determining result of the step S520 is “no”,then it proceeds to execute step S530. If the connection message meetsthe output criteria, which means the determining result of the step S520is “yes”, then it proceeds to execute step S540. In the step S530, acorresponding bypath switch is not conducted and a response is processedby the controlling circuit. In the step S540, the corresponding bypathswitch is conducted to output the connection message, and then itproceeds to execute step S550.

In the step S550, it is determined whether the connected signal needs tobe replied. If the connected signal does not need to be replied, adetermining result of the step S550 is “no”, then it proceeds to executestep S560. If the connected signal needs to be replied, which means thedetermining result of the step S550 is “yes”, then it proceeds toexecute step S570. In the step S560, the connected message is notreplied to the aforementioned device. In the step S570, the connectedmessage is replied to the aforementioned device.

In this embodiment of the invention, the steps S550, S560, and S570 maybe executed by choice. In other words, the steps S550, S560, and S570may be executed or not executed according to a circuit design.

FIG. 6 is a flow chart of an operating method of a transmitting end of ahub according to an embodiment of the invention. Please refer to FIG. 6.In this embodiment of the invention, the operating method of thetransmitting end of the hub includes the following steps. In step S610,it is determined whether the connection interface is coupled to thedevice. If the connection interface is not coupled to the device, whichmeans a determining result of the step S610 is “no”, then it restartsfrom the step S610. If the connection interface in coupled to thedevice, which means the determining result of the step S610 is “yes”,then it proceeds to execute step S620.

In the step S620, it is determined whether the corresponding bypassarbitration circuit receives the connection message and whether theconnection message meets output criteria. If the connection message doesnot meet the output criteria, which means a determining result of thestep S620 is “no”, then it proceeds to execute step S630. If theconnection message meets the output criteria, which means thedetermining result of the step S620 is “yes”, then it proceeds toexecute step S640. In the step S630, a corresponding bypath switch isnot conducted so that the connection message cannot be transmitted. Inthe step S640, the corresponding bypath switch is conducted to outputthe connection message.

An order of the above steps S510, S520, S530, S540, S550, S560, S570,S610, S620, S630, and S640 is used for explanation and the embodiment ofthe invention is not limited thereto. Moreover, details of the stepsS510, S520, S530, S540, S550, S560, S570, S610, S620, S630, and S640 maybe understood from the embodiments of FIG. 1 to FIG. 4 and thus are notrepeated.

Based on the above, the signal bypass circuit of the hub in theembodiment of the invention is coupled to the first pin of the firstconnection interface and the second pin of the second connectioninterface, so as to decide whether to bypass the first pin and thesecond pin based on the first connection message received by the firstpin. In this way, the hub is able to bypass the first pin and the secondpin when the hub cannot intervene between the host and the externaldevice, so as to avoid interfering with the synchronized operationbetween the external device and the electronic device. Furthermore, amonitoring function of the controlling circuit may be removed todecrease the circuit area of the controlling circuit.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the disclosed embodimentswithout departing from the scope or spirit of this invention. In view ofthe foregoing, it is intended that the invention covers modificationsand variations provided that they fall within the scope of the followingclaims and their equivalents.

What is claimed is:
 1. A hub, comprising: a first universal serial bus(USB) c-type interface comprising a first channel configuration pinconfigured to receive a first connection message; a firsttransmission/receipt circuit coupled to the first USB c-type interfaceand receiving the first connection message to provide a connectionconfiguration signal; a second universal serial bus (USB) c-typeinterface comprising a second channel configuration pin configured totransmit the first connection message; a second transmission/receiptcircuit coupled to the second channel configuration pin and configuredto restore the connection configuration signal to the first connectionmessage; a controlling circuit coupled to the first transmission/receiptcircuit and the second transmission/receipt circuit to receive theconnection configuration signal and providing a transmission switchsignal based on the connection configuration signal; and a signal bypasscircuit coupled between the first transmission/receipt circuit and thesecond transmission/receipt circuit in serial, and coupled to thecontrolling circuit to decide whether to bypass the firsttransmission/receipt circuit and the second transmission/receipt circuitbased on the connection configuration signal and the transmission switchsignal.
 2. The hub of claim 1, wherein the signal bypass circuitdisconnects from the first transmission/receipt circuit and the secondtransmission/receipt circuit when the signal bypass circuit does notreceive the connection configuration signal, and the signal bypasscircuit bypasses the first transmission/receipt circuit and the secondtransmission/receipt circuit when the signal bypass circuit receives theconnection configuration signal.
 3. The hub of claim 1, wherein thecontrolling circuit transmits a connected signal through the firsttransmission/receipt circuit when the connection configuration signalneeds to reply the connected signal, and the controlling circuit doesnot transmit the connected signal when the connection configurationsignal does not need to reply the connected signal.